Resistance welding devices comprising a tool configured like a clamp in which two arms supporting respective welding electrodes are distinguished are known today. Conventionally, one of the arms has the capacity of being moved with respect to the tool to enable holding between the arms the components or workpieces on which the welding operation must be performed by passing a welding current through the electrodes when the workpiece is held between the arms of the clamp.
When the welding operation requires attaching a small component, such as a nut on the surface of a metal sheet, in ideal situations in which said sheet is horizontally orientated the small component is placed on the sheet to attach them by welding. This small component is placed by means of shuttles or pistons immediately before the upper electrode exerts pressure on the lower electrode arranged under the sheet.
This approach is not applicable when the welding device incorporating the clamp is assembled on the articulated arm of a robot for the purpose of welding workpieces which can have a spatial orientation different from the horizontal, to one another. In these circumstances the small component does not rest naturally and stably on the sheet.
A first objective of the invention is therefore a device assuring the correct attachment by welding in any spatial orientation.
On the other hand, the small components to be welded must be supplied to the mentioned shuttles or pistons which, like the clamp, must have the same capacity for being orientated according to the needs of each welding operation.
Another objective of the invention is a device which in addition to assuring the correct welding, assures the correct supply of the small components to be welded by means of the clamp.
Another objective of the invention is that this supply is performed simply and such that a significant number of welding operations can be carried out consecutively without needing to intervene with the supply means.
Another objective of the invention is to disclose a device capable of offering the performance pointed out above and which is simple in construction and with an optimum number of components or mobile parts.